Speed density carburetor



Aug. 3; 1948. A. w. ORR, JR

SPEED DENSITY CARBURETOR Filed Feb. .9, 1946 INVENTOR m-ronun Patented Aug. 3, 1948 SPEED DENSITY CARBURETOR Andrew William Orr, Jr., Detroit, Mich., assignor to George M. Holley and Earl Holley Application February 9, 1946, Serial No. 646,559

The object of this invention is to-proportion the fuel to the air in an internal combustion engine. Specifically, the object is to control the 'fuel flow by: (a) the velocity of flow of the fuel to the engine;v (b) the speed of the engine;

engine speed or 'at some speed proportional to engine speed, 26 is the pump outlet. Projecting from the right hand end of the pump I4 is a shaft I6, which carries governor balls I0, which engage to the right with the thrust disc 20- and to the left with the corresponding curved disc 22. The disc 22 is perforated and is moved by the diaphragm 24. Fuel pressure in the outlet 26 is connected through the passage 28 so as to act on the diaphragm 24, which pushes the disc 22 to the right; centrifugal force pushes the disc 22 to the left and opposes the fuel pressure acting on the diaphragm 24. The pressure created by the pump I4 causes the diaphragm 24 to move to the right and'allows fuel to escape from the passage 26 to the chamber 30. Pressure in the chamber 80 acts on the diaphragm 33 and causes the valve 34 to open, compressing spring 4| and allows fuel to return to the fuel entrance through the passage 36. The rear chamber 40, to the right of the diaphragm 33, is connected through the passage 42 to the fuel entrance I0.

A venturi 40 is located in the outlet 26 from the fuel pump I4. A diaphragm 46 forms the lefthand wall of the chamber 50, which communicates through the opening 48 with the throat of the venturi 44.

The chamber 54, located to the left of the diaphragm 636, communicates through the passage 52 with the fuel outlet 26. The diaphragm 46 carries a needle 56, which controls flow through a passage 58, through a restriction 60, to a chamber 62. The movement of the diaphragm 46 to the right is resisted by the compression spring I03. The left-hand wall of chamber 62 is formed by a diaphragm 64. .The diaphragm 64 carries a balance valve 66 and is pushed to the left to the open position by the Claims. (Cl. 123-419) compression spring 96, which permits fuel to escape from the chamber 62, through the passage 60. to the passage 10. Chamber 12 is located on the left-hand side of the diaphragm 64 and is connected through the passage 14 to the chamber 54, and, therefore, to the fuel outlet 26.

When the fuel passes the venturi 44, it divides; a portion goes to the right through the passage 16, passes the valve 18, flows through the passage 80 and rejoins the other branch in the outlet 10. The other branch flows through 44, flows through the passage 82, passes the valve 04 and flows through the'passage 86 and rejoins the fuel outlet at 10. The valve 84 is pushed to the right to the restricted position by an increase in tempera- .ture in the bulb I44. The fuel united in the passage 10 then passes the low-speed control valve 88, which is shown wide open, that is, in its inoperative position; fuel then flows to the chamber 90, the upper wall of which is formed by a diaphragm 92. A chamber 94, located above the diaphragm 92, communicates through a pipe 98 and a restriction I00 with the chamber 30 to the right of diaphragm 24. The diaphragm 92 carries a balance valve I04, and the diaphragm is pushed up by a compression spring I02. The fuel thus escapes through the pipe I06 and discharges through the outlet I00 into the air pipe I I2, downstream of throttle H4. The mixture of fuel and air is then compressed in the enginedriven supercharger I20, which is driven by shaft 202. This mixture is discharged through the inlet manifold I40.

Air enters the pipe I I2 to the left of the throttle valve II4, which throttle is connected through a link II6 with the low-speed control valve 88. A pipe I22 leads out of the supercharger outlet and is connected to a chamber I24. In the chamber I24 are evacuated elements I28, which control the movement of the valve l8. Coupled to these three elements I28 is the single element I30, which is responsive to the exhaust back pressure.

A temperature-responsive element I44 leads out of the supercharger outlet and is connected through a pipe I48 with the pressure responsive elements I50. The elements I are located in a chamber I52. This chamber I52 is connected through the passage I56 with the chamber I24.

- The two chambers I and I62 are also connected to the passage I56. These chambers I60-I62 contain compression springs, which engage with the 3 sion spring I and is located above a diaphragm Ill. This diaphragm I'll forms the upper wall of a chamber "2, which communicates with the fuel line 28. A passage ill is obstructed by a valve I", carried by the diaphragm Ill and the compression spring I reduces the obstruction of valve 118. As the valve lli rises, the obstruction increases. Passage ill communicates with pipe 98, so that a certain quantity of fuel dls-' charged by the pump ll escapes through the passage I14 to the pipe 98 and back to the chamber 3|. through the restriction illl and past the valve 3 to the return passage 36. This flow raises the pressure in the chamber 94 and thus reduces the pressure drop past the restriction formed by valve 84 and 18. Hence the fuel flow is reduced. This is the automatic lean (A. It.) position.

If the lever I" is moved about 90 clockwise from the A. R. position, the opening 2 no longer restricts the connection from passage ill to passage 98. Hence. in this position, the Idle. Cut Or! (I. C. 0.) position, full pressure is applied to the chamber 94, which acting on the diaphragm'92. cuts off all the fuel flow by closing the valve 104.

What I claim is:

, 1. Fuel supply means for an internal combustion engine having an air entrance leading to an inlet manifold comprising a fuel pump, a fuel outlet therefrom, a variable pressure-relief valve for said outlet, engine speed responsive means to regulate said variable pressure whereby as the speed increases the pressure in said outlet increases, two parallel passages leading from said pump to a variable restriction in each of said parallel passages, means responsive to the manifold air pressure and to the pressure in the exhaust manifold connected to one of the restrictions to move said variable restriction into the open position as the exhaust pressure decreases and as the manifold air pressure increases, temperature responsive means connected to the other variable restriction to close said other restriction as the temperature rises.

2. A device as set forth in claim 1 in which there are means responsive to the velocity of the fuel flowing towards said two parallel outlets adapted to admit additional fuel beyond said restrictions.

3. A device as set forth in claim 1 in which there is a valve and a pressure responsive diaphragm controlling said valve. said valve being located in the passage through which the fuel flows from said parallel fuel outlets, a diaphragm responsive to the pressure outlets created by said velocity device. a valve connected to said diaphragm, a fuel passage the flow through which is controlled by said valve. a manually controlled valve in said passage downstream from said dia- -phragm controlled valve, a restricted passage connecting said manually controlled valve with the fuel entrance, a chamber one wall of which is formed by said first mentioned diaphragm and a passage connecting said chamber to the manually controlled valve between said restrictlon and said valve.

4. Fuel supply means for an internal combustion engine having an air entrance leading to'an inlet manifold comprising a fuel pump, a fuel outlet therefrom, a variable pressure-relief valve for said outlet, engine speed responsive means to regulate said variable pressure whereby as the speed increases the pressure in said outlet increases, two parallel passages leading from said pump to a variable restriction in each of said parallel passages, means responsive to the manifold air pressure connected to one of the restrictions to move said variable restriction into the open positionas the exhaust pressure decreases and as the manifold air pressure increases, temperature responsive means connected to the other variable restriction to close said other restriction as the temperature rises.

5. A device as set forth in claim 4 in which there are means responsive to the velocity of the fuel flowing towards said two parallel outlets adapted to admit additional fuel beyond said restrictlons.

; ANDREW WH-IJAM ORR, JR.

REFERENCES CITED The following references are of record in the file 'of. this patent:

UNITED STATES PATENTS FOREIGN PATENTS Country Date Great Britain June 4, 1935 Number Number 

